[Bldg-sim] LEED - What does it take?

RobertWichert robert at wichert.org
Mon Jan 21 07:33:43 PST 2013


Thanks Vikram,

Your thoughts are right on point and resonate with my instinctive 
reaction too.


Cheers!



Robert Wichert P.Eng. LEED AP BD&C
+1 916 966 9060
FAX +1 916 966 9068







===============================================

On 1/21/2013 6:43 AM, Sami, Vikram wrote:
>
> My two five cents -- adding to the many cents already thrown in the pot.
>
> ·LEED & Appendix G at this point are based on energy cost -- not raw 
> BTUs or carbon. So the relative costs of your fuel mix will have an 
> effect on final scores (in a place where electricity is cheap and 
> heating fuel is not -- you are likely going to have less credit for 
> your SEER rating). I don't agree with it, but that's how the system is 
> set up.
>
> ·The effectiveness depends on your baseline energy usage. For example 
> -- if you have a building that has very small HVAC component, even a 
> 50% reduction won't get you to 10% overall.
>
> ·LEED addresses consumption and not efficiency (which is a good 
> thing). So you get credit for 'driving less'. Hours that you don't 
> need to run your HVAC = money in your pocket (the envelope leg of 
> Nick's tripod analogy).
>
> ·It also depends on other factors like how you deliver the energy. For 
> example -- using hydronic cooling & heating will likely save you more 
> energy than an all air system with a higher EER on the chiller. Using 
> a waterside economizer goes back to the 'driving less' analogy. 
> Hydronic systems are also less prone to reheat (simultaneous heating & 
> cooling) issues that you have with all air systems.
>
> The way I like to approach LEED projects is to go after the intent of 
> the credits rather than the point -- you'll be surprised at how often 
> you end up with a higher LEED score when you do.
>
> Apologies to Robert if this doesn't directly respond to the original 
> question.
>
> **
>
> *Vikram Sami*, LEED AP BD+C
>
> Sustainable Design Analyst
>
> 1315 Peachtree St. NE, Atlanta, GA 30309
>
> t: 404-443-7462    f: 404.892.5823 e: vikram.sami at perkinswill.com 
> www.perkinswill.com <http://www.perkinswill.com/>
>
> *Perkins+Will.*Ideas + buildings that honor the broader goals of society
>
> *From:*bldg-sim-bounces at lists.onebuilding.org 
> [mailto:bldg-sim-bounces at lists.onebuilding.org] *On Behalf Of *Nick Caton
> *Sent:* Wednesday, January 16, 2013 8:09 PM
> *To:* Dennis Knight; RobertWichert
> *Cc:* bldg-sim at lists.onebuilding.org; EnergyPro at yahoogroups.com
> *Subject:* Re: [Bldg-sim] LEED - What does it take?
>
> Man, every time I start a reply 3 more have come out, haha!  I think 
> we're all pretty much on the same page though =). This is largely 
> written in response to Robert's most recent reply:
>
> Applying 10% improvement to lighting/mechanical equipment/envelope is 
> merely a strategy for achieving performance figures in the right 
> ballpark once energy modeling begins.  No more and no less.  I can 
> attest this has worked well for me in the past, but I _never_ meant to 
> imply "..and you're done."
>
> This is just a means of getting the ball rolling and ensuring the 
> important decision makers understand they have a role to play.
>
> I agree completely regarding the limits of SEER and every other 
> standardized efficiency rating I've worked with.  Seasonal and steady 
> state efficiencies are NEVER direct indicators of actual system 
> consumptions, they are merely representations of performance under 
> specific conditions. That said, they do have a useful time & place 
> which occurs at the beginning of a project, before a more detailed 
> analysis can be made with energy models or otherwise.  SEER may or may 
> not be an inadequate efficiency metric for your specific climate, but 
> that doesn't change what defines your baseline equipment.
>
> If the goal is simply to reduce heating and cooling energy 
> consumptions of your HVAC systems by XX%, and I can't build something 
> resembling the final design for an energy model, I simply can't offer 
> a better answer than "improve your heating and cooling efficiencies by 
> XX%," recognizing this alone will not get you there if your lighting 
> consumptions and envelope performance do not do their part.
>
> A black and white answer to what minimum performance is required of 
> any system for any specific LEED project goal is truly unapproachable 
> until you start the energy model that will determine the results ;).
>
> As it happens however, I can answer Robert's most recent hypothetical 
> almost directly:  I have performed a preliminary study for a building 
> in the vicinity of El Paso, TX using 15 SEER AHU's with energy 
> recovery.  I determined a 30% LEED improvement would have been 
> attainable using an envelope matching 90.1 baseline constructions, but 
> this entailed a roughly 50% LPD reduction (I would have performed the 
> lighting design and can attest this was achievable), and a healthy 
> laundry list of EEM's for mechanical, with a heavy service hot water 
> equipment load helping things along.
>
> So to wrap up, I'd say 15 SEER units absolutely can be one part of a 
> bigger picture achieving a 10% LEED performance rating.
>
> Apologies for the walls of text... sometimes the quick & easy answer 
> is "there aren't any quick and easy answers!"  Hope this discussion is 
> helpful to you and yours in any case!
>
> ~Nick
>
> cid:489575314 at 22072009-0ABB**
>
> **
>
> *NICK CATON, P.E.*
>
> SENIOR ENGINEER
>
> Smith & Boucher Engineers
>
> 25501 west valley parkway, suite 200
>
> olathe, ks 66061
>
> direct 913.344.0036
>
> fax 913.345.0617
>
> www.smithboucher.com__
>
> *From:*Dennis Knight [mailto:dknight at wholebuildingsystems.com]
> *Sent:* Wednesday, January 16, 2013 6:24 PM
> *To:* RobertWichert
> *Cc:* Nick Caton; bldg-sim at lists.onebuilding.org; 
> EnergyPro at yahoogroups.com
> *Subject:* Re: [Bldg-sim] LEED - What does it take?
>
> Robert,
>
> Simple answer is "No" - that is my point - it more than likely never 
> will.  You have to include all of your proposed energy conservation 
> measures that you are likely to apply into a single model with your 
> user and climate/local specific schedules and profiles included to see 
> what the aggregated savings maybe.  You can run multiple models 
> changing only one component to do some sensitivity analysis to see 
> what variables/measures may give you more dramatic changes in total 
> energy consumption, cost, carbon  emissions, indoor comfort, life 
> cycle cost, life cycle assessment, etc.  (which ever your client and 
> you are using as your decision making criteria).
>
> As for the question regarding 10% energy reduction using 15 SEER 
> equipment: I've gotten 10% better energy performance using 90.1 
> minimum SEER compliant equipment and effecting change in lighting 
> power density, lighting controls, controllable plug loads and better 
> envelope/less infiltration, better ventilation and properly downsizing 
> the mechanical systems.  You do not always have to improve the 
> mechanical efficiency of the HVAC equipment to achieve an energy 
> efficiency improvement target.  It is a whole building analysis that 
> the owner's O&M behavior can have a major impact on.  Conversely, I've 
> had bleeding edge efficiency and complexity in the energy using 
> systems at some facilities and the buildings perform worse than an 
> minimum code compliant building  or a local median EUI when a 
> custodian who knows how to turn things off at night could have done 
> better - when the owner does not understand how the design team 
> intended the building to be operated when they made their analysis. 
>  For example, I just investigated a net zero energy house that was 
> donated to an international non-profit.  It has 22 SEER geothermal 
> heat pumps, an envelope so tight it had no air measurable leakage at 
> 80 pascals, LED lighting, solar water heater, energy recovery 
> ventilator, solar PV, SIPS panel wall system, commercial grade low e 
> windows and a sophisticated energy monitoring system.  It is built 
> right next to a conventionally built house, stick framed, minimum 
> residential code compliant construction with 13 SEER air source heat 
> pumps.  Both are occupied by single mothers with two children.  The 
> net zero house has worse energy performance than the code minimum 
> house almost entirely due to occupant behavior. I personally did not 
> believe you could operate that house such that it would ever consume 
> much energy, but you can.  In this case the owner was not determined 
> until after the house was constructed and did not have a stake in the 
> design and was not trained on the special features of the house when 
> it was offered to her.  Now that she has been educated I can see some 
> reductions - but the house is still falling way short of its goal of 
> net zerobecause the owner is just unwilling to change her lifestyle no 
> matter what the nergy costs are.
>
> Dennis
>
> On Wed, Jan 16, 2013 at 6:28 PM, RobertWichert <robert at wichert.org 
> <mailto:robert at wichert.org>> wrote:
>
> I suppose the modeling software and how it treats energy might have 
> something to do with it too (Note to CA and TDV), but for starters the 
> modeling software will look at actual conditions in the particular 
> place where the project is located.  As an absurd case, if there was 
> no cooling needed, an infinite SEER would show no improvement.  SEER 
> is for "typical" and each project is not necessarily typical.  For 
> somewhere with a high cooling demand, SEER should have a greater 
> effect, but cooling is only a small part of the energy budget.
>
> I can appreciate that with "10% better walls, 10% better windows (or 
> how about 10% less windows), 10% lower lighting wattages, 10% more 
> efficient hot water, all compared to the standard, you could get 10% 
> better using a SEER 14.3, but I have never gotten that result.  I 
> suppose that I need to look harder at the other legs on the stool.  
> For me, I need SEER 17 to get to 10% better in California with a 
> somewhat lopsided stool.  I am curious what experience others have.
>
> The theoretical answer may be "Make everything else use 10% less 
> energy than standard and have a SEER 14.3 AC unit, and you're done" 
> but to be honest, that doesn't ever work for me.
>
> Maybe a better question is; have you ever gotten 10% better than 
> ASHRAE 90.1 with a 15 SEER AC system? In a real project with real 
> people fighting over costs, etc.?
>
>
>
> Robert Wichert P.Eng. LEED AP BD&C
> +1 916 966 9060  <tel:%2B1%20916%20966%209060>
> FAX+1 916 966 9068  <tel:%2B1%20916%20966%209068>
>   
>   
>   
>   
>   
>   
>   
> ===============================================
>
> On 1/16/2013 2:25 PM, Dennis Knight wrote:
>
>     Robert,
>
>     SEER is a seasonal energy efficiency ratio and is unitless.  It is
>     the "cooling output during a typical cooling-season divided by the
>     total electric energy input during the same period":
>     http://en.wikipedia.org/wiki/Seasonal_energy_efficiency_ratio.  A
>     unit with 10% or better seasonal cooling energy efficiency over a
>     13 SEER unit would have a SEER rating of 14.3 or greater (1.1x13)
>     if all other operating parameters were held constant.  See link
>     for definitions and other references.
>
>     Dennis
>
>     On Wed, Jan 16, 2013 at 5:11 PM, RobertWichert <robert at wichert.org
>     <mailto:robert at wichert.org>> wrote:
>
>     My current project has very good windows, "standard" walls, you're
>     right about the lighting, it's right on budget (but residential
>     doesn't really have a budget, so the small common areas are right
>     on budget), better than standard roof.
>
>     I absolutely agree with you, Nick, on achieving 10% better, but
>     all the trades point to the others.  It's kind of comical, actually.
>
>     I guess my question on this list could be rephrased, using your
>     approach, as "What SEER is 10% better than SEER 13?"
>
>
>
>
>     Robert Wichert P.Eng. LEED AP BD&C
>     +1 916 966 9060 <tel:%2B1%20916%20966%209060>
>     FAX +1 916 966 9068 <tel:%2B1%20916%20966%209068>
>
>
>
>
>
>
>
>     ===============================================
>
>     On 1/16/2013 12:34 PM, Nick Caton wrote:
>
>     A very simple way of looking at LEED & energy, which I come back
>     to often for discussions on that level, is to consider a
>     building's performance like a tripod with three important legs:
>      Lights, Mechanical, and Envelope.  If any of those legs is too
>     short, the tripod falls over.
>
>     Building on that analogy, to do 10% better than a LEED baseline, a
>     good starting place is to have at least:
>     -  10% better lighting (10% lower LPD),
>     -  10% better HVAC & hot water heating (10% better efficiencies), and
>     -  10% better envelope (10% more insulation in walls/roof, 10%
>     better windows).
>     For each of these, you can source the baseline/prescriptive levels
>     from the standard of your choosing.
>
>     Overperforming in one area can sometimes make up for
>     underperfomance in another, but with diminishing returns.  Amazing
>     HVAC equipment/design has a harder time shining when you have a
>     poor envelope and/or the lighting designer treats LPD's as a
>     "budget" they have to use up.  For such reasons, it's advisable to
>     always consider building performance in holistic fashion in
>     early/broader discussions.
>
>     That's my (simple) take anyway!
>
>     ~Nick
>
>     NICK CATON, P.E.
>     SENIOR ENGINEER
>
>     Smith & Boucher Engineers
>     25501 west valley parkway, suite 200
>     olathe, ks 66061
>     direct 913.344.0036 <tel:913.344.0036>
>     fax 913.345.0617 <tel:913.345.0617>
>     www.smithboucher.com <http://www.smithboucher.com>
>
>
>     -----Original Message-----
>     From: bldg-sim-bounces at lists.onebuilding.org
>     <mailto:bldg-sim-bounces at lists.onebuilding.org>
>     [mailto:bldg-sim-bounces at lists.onebuilding.org
>     <mailto:bldg-sim-bounces at lists.onebuilding.org>] On Behalf Of
>     RobertWichert
>     Sent: Wednesday, January 16, 2013 9:24 AM
>     To: EnergyPro at yahoogroups.com <mailto:EnergyPro at yahoogroups.com>;
>     bldg-sim at lists.onebuilding.org <mailto:bldg-sim at lists.onebuilding.org>
>     Subject: [Bldg-sim] LEED - What does it take?
>
>     I know that LEED is way more than just energy, and energy is way
>     more than just equipment, but just for a basis, what SEER and EER
>     do people have to use to get 10% better than ASHRAE 90.1 to
>     qualify for LEED?  I also know that you don't have to use ASHRAE
>     90.1, but that is what I am doing.
>
>     So, what does it take?
>
>     My shot - Residential Apartment, individual DX units, 17 SEER and
>     13 EER in California CZ 12 (Mostly cooling).
>
>        Next?
>
>
>     --
>     Robert Wichert P.Eng. LEED AP BD&C
>     +1 916 966 9060 <tel:%2B1%20916%20966%209060>
>     FAX +1 916 966 9068 <tel:%2B1%20916%20966%209068>
>
>
>
>
>
>
>
>     ===============================================
>
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>
>     -- 
>     M. Dennis Knight, P.E.
>
>     Founder & CEO
>
>     *W*hole *B*uilding *S*ystems, LLC
>
>     P.O. Box 1845
>
>     Mt. Pleasant, SC 29465
>
>     Phone: 843-437-3647 <tel:843-437-3647>
>
>     Email: dknight at wholebuildingsystems.com
>     <mailto:dknight at wholebuildingsystems.com>
>
>     Website: www.wholebuildingsystems.com
>     <http://www.wholebuildingsystems.com>
>
>
>
> -- 
> M. Dennis Knight, P.E.
>
> Founder & CEO
>
> *W*hole *B*uilding *S*ystems, LLC
>
> P.O. Box 1845
>
> Mt. Pleasant, SC 29465
>
> Phone: 843-437-3647
>
> Email: dknight at wholebuildingsystems.com 
> <mailto:dknight at wholebuildingsystems.com>
>
> Website: www.wholebuildingsystems.com 
> <http://www.wholebuildingsystems.com>
>

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